Silicon optical waveguides have potential as a platform for ultra-small photonic integrated circuits (PICs). In a typical structure, a silicon core with high refractive index is surrounded by a low refractive index material, typically silicon dioxide. This structure forms an optical waveguide, typically used at communications wavelengths such as the 1310 nm or 1550 nm bands, wavelengths for which the silicon and silicon dioxide are transparent. Typical silicon PIC chips use a lithographically-defined layout of single mode and multimode waveguide elements, wherein the whole forms a photonic circuit. Alternate materials systems that may be used can include Si, GaAs, InP, LiNbO3, PLZT, SiN, SiON.
SiPh (silicon photonics) PICs technology is used to build large switch matrices. Switches up to 32×32 have been demonstrated on this technology. A SiPh switch core of this size and with optical packet switch capability can replace an electrical switch used in data centers, for example a circuit switch, packet router and an optical transport network (OTN) switch.
Due to the intrinsic properties of SiPh material system, the optical path has a relatively high optical loss. As a result, multistage photonic integrated devices can demonstrate excessive optical loss. This optical loss can prevent the application of SiPh PIC (photonic integrated circuit) chip to replace electrical switch core in data centers.
Accordingly, there may be a need for an assembly that is not subject to one or more limitations of the prior art.
This background information is intended to provide information that may be of possible relevance to the present invention. No admission is necessarily intended, nor should be construed, that any of the preceding information constitutes prior art against the present invention.